In the previous version to this one (3.4.6), when you uploaded a picture to the gallery did it not either have an link you could share in a topic or when you posted that topic, gave you the option to choose gallery photos to display?

The way it is currently, you would have to upload it into a topic as well as upload it in the gallery, you are then storing two versions of the same picture on your server.

Am I missing something?

There was a option button in the old version, that had the share links as different types : html, bbcode, image or page link. 

I wish we had those back too.

"face palm"

In the editor window, go to lower right "insert other media" button. Pick existing attachment, and the option to pick from your gallery album should be there.

Finally figured it out !